Investigation of the thermal remagnetization in sintered hard magnets

The maximum thermal remagnetization (TR) after dc-demagnetization was studied at sintered RE/T hard magnets and at barium ferrite. We found very large TR-effects for SmCo/sub 5/, large effects for hard ferrites, medium for NdFeB and a very low effect for Sm/sub 2/Co/sub 17/ magnets. The experimental results are interpreted on the basis of a theory taking into account the local fluctuations of the internal magnetic field as well as the internal demagnetization effects. The relevant model parameters were estimated for SmCo/sub 5/ and barium ferrite.